Methods of sulfurizing metal containing particles

ABSTRACT

Methods of sulfurizing metal containing particles in the absence of hydrogen are described. One method includes contacting a bed of metal containing particles with a gaseous stream comprising hydrogen sulfide and inert gas under reaction conditions sufficient to produce sulfided metal containing particles. The gaseous stream is introduced into a vertical reactor at an inlet positioned at the bottom portion of the reactor and any unreacted hydrogen sulfide and inert gas is removed at an outlet positioned above the inlet. The sulfided metal containing particles can be removed from the reactor and stored.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 15/518,361 filed Apr. 11, 2017, which is a national phase under 35U.S.C. § 371 of International Application No. PCT/US2015/055656, filedOct. 15, 2015, which claims the benefit of priority to U.S. ProvisionalPatent Application No. 62/064,697, filed Oct. 16, 2014, the entirecontents of each application are hereby incorporated by reference intheir entirety.

BACKGROUND OF THE INVENTION A. Field of the Invention

The invention generally concerns the sulfiding of metals, moreparticularly, the sulfiding of metal containing particles in the absenceof hydrogen.

B. Description of Related Art

Metals compounds are commonly used in new or regenerated absorbentsand/or catalysts to remove undesirable metal materials (for example,heavy metals such as mercury) from gases and liquids that pass over theabsorbent. The metals, however, upon preparation usually exist in a formthat renders them inactive or of low activity. To increase the activityof the metals, the absorbents and/or catalysts are treated with sulfuror a sulfiding agent to convert the metals to the more active metalsulfides. This process can be referred to as sulfurating, sulfurizationor sulfiding of metal catalysts, adsorbents, and absorbents. Inconventional processes, sulfurization can be performed in-situ orex-situ.

A common way to produce metal sulfides is to react a metal oxide with agaseous sulfide, elemental sulfur, organic sulfur compounds that candecompose to hydrogen sulfide, or combinations thereof. Many of theseprocesses are performed in the presence of hydrogen to promote fullsulfurization of the metal oxide. In a conventional in-situsulfurization of absorbents or catalysts that include metals, thesulfurization is performed in a reactor, where the absorbent or catalystis used, or in the immediate vicinity of the reactor. For example, inthe top of the reactor or zones that are more or less in directcommunication with the reactor requiring the sulfurization to beperformed under operating conditions (for example, temperature andpressure) that are imposed at least partially by the operatingconditions of the reactor itself, or annexes of the reactor. In situsulfurizing has the disadvantages of high costs, prolonged time forsulfurization and environmental pollution.

In a conventional ex-situ sulfurization process, the metal containingabsorbent or catalyst can be treated with an inorganic or organic sulfursolvent in the presence of hydrogen. This occurs outside of the reactorand outside of the immediate vicinity of the reactor (e.g., separateroom or location form the reactor). The sulfided material can then betreated with a passivating agent that can lessen the pyrophoric and/orself-heating nature of the sulfided material. The passivated sulfidedmetal material can then be transported to an absorption unit prior tostarting the hydroprocessing or absorption reaction.

Many conventional processes treat the absorbent with a sulfurizationagent, and then treat the resulting sulfided material with hydrogen toform metal sulfides. For example U.S. Pat. No. 8,197,695 to Cousins etal.; U.S. Pat. No. 8,177,983 to Cousins and U.S. Pat. No. 7,645,306 toKanazirev describe processes that use absorbents that are sulfidedduring the process of removing heavy metals from a stream by passing astream that contains the sulfiding agent and heavy metal over theabsorbent.

U.S. Patent Application Publication No. 2013/0053234 to Fish et al.describes a method of preparing a sorbent that includes applying a layerof copper compound on the surface of the sorbent through dipping orspraying the support material with a slurry of basic carbonate. Thecoated support is dried and sulfided using conventional processes in anex-situ vessel through which a sulfiding agent of hydrogen sulfide,alkali metal sulfide, ammonium sulfide, elemental sulfur or apolysulfide is passed. Hydrogen gas and carbon monoxide can be presentwhen the sulfiding is performed at temperatures below 150° C. andparticularly below 100° C.

U.S. Patent Application Publication No. 2012/0103912 to Hetherington etal. describes preparation of a sorbent for heavy metals that containsulfides of vanadium, chromium, manganese, iron, cobalt or nickel. Thesorbent is prepared by reducing a sorbent precursor containing a metalsulfide precursor compound of vanadium, chromium, manganese, iron,cobalt or nickel, and optionally a support or binder, to a loweroxidation state with a hydrogen containing gas to form a reducedcomposition, and sulfiding the reduced composition with a sulfidingcompound to form the sorbent.

U.S. Patent Application Publication No. 2011/0226700 to Hetherington etal. describes preparation of sorbents that contain copper sulfides bysulfiding a sorbent precursor comprising a copper sulfide precursorcompound and a binder and/or support material with a gas mixturecomprising hydrogen sulfide to form a sulfided copper material, andreducing the sulfided copper material to a lower oxidation state to formthe sorbent.

Conventional catalyst sulfiding processes are described in U.S. Pat. No.6,100,216 to Dufresne et al. which describes a process forpresulfurizing a hydrocarbon treatment catalyst and/or forpreconditioning a catalyst, that includes one or two stages ofincorporating sulfur into the pores of a hydrocarbon conversion catalystconducted off-site in at least one moving zone that contains a catalystwith hydrogen and either hydrogen sulfide, sulfur, or a sulfur compoundcapable of evolving nascent hydrogen sulfide.

Some conventional processes require a protective material be applied tothe metal sulfide catalyst after the sulfurization process. For example,U.S. Pat. No. 3,453,217 describes a method of preparing a hydrotreatingcatalyst and protecting the metal sulfides of the hydrotreating catalystby introduction of a protective material into the pores of the catalyst.

International Patent Application Publication No. WO 2013/136046 toCousins et al. describes a method for sulfiding copper sorbents. Themethod includes the steps of: (i) contacting a sorbent precursormaterial containing one or more sulfidable copper compounds, with asulfiding gas stream comprising hydrogen sulfide to form a sulfidedsulfur-containing sorbent material, and (ii) subjecting the sulfidedsulfur-containing sorbent material to a heating step in which it isheated to a temperature above that used in the sulfiding step and >110°C., under an inert gas selected from nitrogen, argon, helium, carbondioxide, methane, and mixtures thereof, said inert gas optionallycomprising hydrogen sulfide.

While there are numerous ex situ methods of sulfurizing metal catalystsand sorbents they typically use hydrogen, excess amounts of sulfidingagents, and, in some cases, a passivating agent. Hydrogen is relativelyexpensive to make, separate, and/or procure, which makes theconventional processes expensive. Furthermore, when a sulfidingprecursor is used, higher temperatures are required for thesulfurization process to decompose the sulfiding precursor to hydrogensulfide. Many processes for ex situ sulfurization use multiple stages.Processing in multiple stages typically use mechanical means for movingand transporting the catalyst and sorbents, which can cause undesiredphysical abrasion and deterioration.

SUMMARY OF THE INVENTION

A solution to the problems associated with sulfurizing metal containingparticles has been discovered. The solution resides in the ability tosulfide fragile metal containing particles in the absence of reducingagents, preferably in the absence of hydrogen, while providing hydrogensulfide gas directly to the metal containing particles at a relativelylow temperature. Reducing agents can include carbon monoxide and organicacids such as, for example, formic acid, methyl formate and ethylformate. The present invention solves the problem of having to generatehydrogen sulfide in situ at high temperatures and the control theexothermic nature of the sulfiding process. The solution also resides inthat little, or no, excess hydrogen sulfide is used in the process.Notably, it was discovered that the sulfurization can take place withoutmovement of the particle bed, thus the metal containing particles arenot damaged during the sulfurization process. The metal containingparticles can be comprised in a sorbent or a catalyst. In some preferredaspects of the invention, the sulfided metal containing particles areused as a sorbent.

In one aspect of the present invention, a method of sulfurizing metalcontaining particles in the absence of hydrogen is described. The methodincludes (a) obtaining a vertical reactor comprising a bed of metalcontaining particles; (b) contacting the bed of metal containingparticles with a gaseous stream comprising hydrogen sulfide and inertgas under reaction conditions sufficient to produce sulfided metalcontaining particles, and (c) removing sulfided metal containingparticles from the reactor. The gaseous stream can be introduced intothe vertical reactor at an inlet positioned at the bottom portion of thereactor and any unreacted hydrogen sulfide and inert gas is removed atan outlet positioned above the inlet. Contacting can be performed atpressure from ambient pressure to 195 kPa. Steps (a), (b), (c), or anycombinations thereof are performed in the absence of hydrogen gas. Insome aspects of the invention, the method can be performed off site. Themetal containing particles in the reactor prior to contacting withhydrogen sulfide are particles that have not previously been sulfided,are particles that need to be re-sulfided, or are a combination thereof.In some instances, the metal containing particles prior to contactingwith hydrogen sulfide are supported particles. The support can be arefractory oxide, carbon, titanium dioxide, or any combination thereof.In one instance, the metal containing particles are unsupportedparticles. The metal in the metal containing particles can be a metal ormetal compound from Group VIII or Group IB of the Period Table. Anon-limiting example of the Group VIII metal is iron (Fe). Anon-limiting example of the Group IB metal is copper (Cu). The inert gascan include methane, nitrogen, carbon dioxide, or any combinationthereof. In some instances, a molar ratio of the combination of nitrogenand carbon dioxide to hydrogen sulfide ranges from 5:1 to 50:1, with aratio of 25:1 being preferred. In some instances, the gaseous streamcomprises about 1 to 20 vol. % or 2 to 20 vol. % of hydrogen sulfide.During contacting, the metal containing particles remain substantiallystationary. In some instances, a linear weight hourly space velocity(LHSV) of the gaseous stream is used such that no fluidization orebullition of the bed occurs, but a majority of the metal containingparticles are in motion during contacting. In an alternative aspect ofthe invention, the metal containing particles static are relative toeach other, and thus, are not mixed during contacting. In some aspectsof the invention, the metal containing particles are heated to 50 to200° C. prior to and/or during contact with hydrogen sulfide. Thecontacting conditions can include temperature and pressure. A contactingtemperature is 250° C. or less, 200° C. or less, 150° C. or less, 100°C. or less, or from about 20 to 250° C. The temperature during theprocess can be controlled by one or more heating elements alone or incombination with one or more cooling elements. During the contactingprocess, 10%, 20%, 30%, 40%, 50%, 80% or up to 90% the bed of metalcontaining particles is converted into the sulfided metal containingparticles. In some instances, a majority of the produced sulfided metalcontaining particles are positioned closer to the inlet when compared tothe outlet of the reactor. In some aspects of the invention, at least 1%and less than 50% of the produced sulfided metal containing particlesare removed from the bottom portion of the reactor and additional metalcontaining particles are added to the bed. The method can furtherinclude discontinuing the addition of metal particles to the bed,contacting the metal particles remaining in the bed with the gaseousstream that includes hydrogen sulfide and inert gas to convert theremaining metal containing particles into the sulfided metal containingparticles and removing any unreacted hydrogen sulfide and inert gas atan outlet positioned above the inlet and removing substantially all ofthe sulfided metal containing particle from the bottom portion of thereactor, wherein 90% or more of the removed metal containing particlesare converted into the sulfided metal containing particles. Steps (a)through (c) of the process can be repeated for a desired amount of time.For example, 2, 3, 4, 5 or more cycles, or until a sufficient amount ofsulfided particles are produced. In some instances, 50%, 60%, 70%, 80%,90% or more of the metals in the metal containing particle are convertedinto metal sulfides. In some instances, steps (a), (b), or (c) or anycombinations thereof are done in the absence of oxygen, water, or bothto minimize the formation of elemental sulfur and/or oxidation of thesulfided metal containing particles. In preferred embodiments, at leaststep (b) is performed in the absence of oxygen, water, or both tominimize the formation of elemental sulfur and/or oxidation of thesulfide metal containing particles.

In another aspect of the invention, a method of sulfurizing metalcontaining particles can include (a) contacting a bed comprising metalcontaining particles with a gaseous stream comprising hydrogen sulfideat conditions sufficient to produce sulfided metal containing particles,and partially sulfided metal containing particles in the bed, (b)removing a portion of the sulfided metal containing particles from thebed; and (c) providing unsulfided metal containing particles to the bedupstream of the partially unsulfided metal particles. The gaseous streamcan be introduced into the bottom portion of the bed and any unreactedhydrogen sulfide is removed through an outlet proximate an upper portionof the bed. Contacting can be performed at pressure from ambientpressure to 195 kPa. Steps (a), (b), (c) or any combinations thereof canbe performed in the absence of hydrogen gas. The sulfided metalcontaining particles can be downstream of, or below, the partiallysulfided metal containing particles. In some aspects of the invention atleast at least 25%, 50%, 75% or 90% of the initial amount of metalcontaining particles are sulfided. In some aspects of the invention,unsulfided metal containing particles can be upstream or above thepartially sulfided metal particles. Thus, the particle bed can have atleast three layers of metal containing particles with the partiallysulfided metal containing particles between the sulfided metal particlesand the unsulfided metal containing particles. In some aspects of theinvention, removal of sulfided metal containing particles and additionof unsulfided metal containing particles can be performed sequentiallyor simultaneously. In some aspects of the invention, a majority of theproduced sulfided metal containing particles can be removed from thebottom portion of the particle bed. In a particular aspect,substantially all of the metal containing particles are removed from thebed, and 100% of the removed metal containing particles are sulfided.The gaseous stream can flow in an upwardly direction through the metalcontaining particles bed. In some embodiments, the bed is vertical(i.e., the height of the bed is greater than its width), and the gaseousstream flows from the bottom portion of the bed, through the bed, andthen out the upper portion of the bed. The gaseous stream that exits theupper portion can include unused hydrogen sulfide, water, and, in someinstances, inert gas. The metal in the particles and contactingconditions (e.g., temperature and pressure) can be the same as thosedescribed above and throughout the specification.

The terms “off-site” or “ex situ” refer to a location that is separatefrom the location where the metal containing particles are intended foruse or not within a reactor where the metal containing particles areintended for use. For example, a location that is remote from a refiningfacility or natural gas facility, a vessel that is in the same buildingas the reactor but physically isolated from the reactor, or a vesselthat is in a separate building from the reactor.

The term “mixed” means that the metal containing particles are moved bya force such that the particles position with respect to each other israndomized.

The terms “ebullition” or “fluidization” mean that the metal containingparticles are suspended and kept in motion by an upward flow of a gas.For example, the metal containing particles move up and down and changeposition with respect to each other when contacted with an upward flowof a gas.

The terms “unsulfided metal containing particles” refer to unsulfidedmetal particles and metal particles that need to be re-sulfided.

The Periodic Table refers to the Chemical Abstracts Service version ofPeriodic Table.

The term “sorbent” includes adsorbents and absorbents.

The term “about” or “approximately” are defined as being close to asunderstood by one of ordinary skill in the art, and in one non-limitingembodiment the terms are defined to be within 10%, preferably within 5%,more preferably within 1%, and most preferably within 0.5%.

The term “substantially” and its variations are defined as being largelybut not necessarily wholly what is specified as understood by one ofordinary skill in the art, and in one non-limiting embodimentsubstantially refers to ranges within 10%, within 5%, within 1%, orwithin 0.5%.

The terms “inhibiting” or “reducing” or “preventing” or “avoiding” orany variation of these terms, when used in the claims and/or thespecification includes any measurable decrease or complete inhibition toachieve a desired result.

The term “effective,” as that term is used in the specification and/orclaims, means adequate to accomplish a desired, expected, or intendedresult.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims or the specification may mean “one,” but itis also consistent with the meaning of “one or more,” “at least one,”and “one or more than one.”

The words “comprising” (and any form of comprising, such as “comprise”and “comprises”), “having” (and any form of having, such as “have” and“has”), “including” (and any form of including, such as “includes” and“include”) or “containing” (and any form of containing, such as“contains” and “contain”) are inclusive or open-ended and do not excludeadditional, unrecited elements or method steps.

The methods of the present invention can “comprise,” “consistessentially of,” or “consist of” particular ingredients, components,compositions, etc. disclosed throughout the specification. With respectto the transitional phase “consisting essentially of,” in onenon-limiting aspect, a basic and novel characteristic of the methods ofthe invention is the ability to sulfide metal containing particles offsite under relatively low temperatures and in the absence of hydrogen.

Other objects, features and advantages of the present invention willbecome apparent from the following figures, detailed description, andexamples. It should be understood, however, that the figures, detaileddescription, and examples, while indicating specific embodiments of theinvention, are given by way of illustration only and are not meant to belimiting. Additionally, it is contemplated that changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C are schematics of a method of the present invention forsulfurization of metal containing particles.

FIGS. 2A-2C are schematics of sulfurizing metal containing particlesemploying mixing methods.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and will herein be described in detail. Thedrawings may not be to scale. It should be understood that the drawingsand detailed description thereto are not intended to limit the inventionto the particular form disclosed, but to the contrary, the intention isto cover all modifications, equivalents and alternatives falling withinthe spirit and scope of the present invention as defined by the appendedclaims.

DETAILED DESCRIPTION OF THE INVENTION

A method to sulfide or re-sulfide metal containing particles usinghydrogen sulfide in the absence of hydrogen at relatively mild andnon-destructive conditions has been discovered. The discovery solves theproblems of conventional processes, which typically provide thesulfurizing agent (1) to the top of the reactor, (2) under fluidizing orebullition conditions, and/or at (3) high temperatures, which can leadto incomplete sulfurization of the particles and/or degradation of themetal compounds. The present invention does not require the particles tobe mixed or moved during contact of the particles with gaseous hydrogensulfide. Without wishing to be bound by theory, it is believed thatmixing or substantially moving the particles can damage the metalcontaining particles (for example, crush or break the particles), whichmay reduce the surface area of the particles, create increased pressuredrop in the sorbent bed, and/or reduce the pore size of the particlessuch that incomplete sulfurization of the metals occurs. Notably, theinvention provides a mild process for complete, or substantiallycomplete, sulfurization of metals in the metal containing particlesunder static or non-fluidizing conditions.

These and other non-limiting aspects of the present invention arediscussed in further detail with reference to the Figures.

The present invention provides a process for sulfurizing metalcontaining particles that have not been sulfided, particles that need tobe re-sulfided or a combination thereof. The sulfurization is done inthe absence of reducing agents or oxidizing agents, preferably in theabsence of hydrogen gas, oxygen, water or any combination thereof, andmost preferably in the absence of hydrogen gas. The metal containingparticles can be supported or unsupported particles. The metals includeone or more metals from Group VIII, Group IB of the Periodic Table, orany combination thereof. The metals can be of mixed valency, singlevalency, or both. Non-limiting examples of metals from Group VIIIinclude iron (Fe), ruthenium (Ru), cobalt (Co), rhodium (Rh), nickel(Ni), palladium (Pd) and platinum (Pt), with Fe being preferred.Non-limiting examples of metals from Group IB include copper (Cu), gold(Au) and silver (Ag), with Cu being preferred. The metals can be in theform of an oxide (for example, iron oxide or copper oxide), hydroxide,carbonate, hydroxycarbonate or any mixture thereof. The metal containingparticles can be any shape or size. In embodiments where the metalcontaining particles are in a shaped form, they can include a support, abinder or any combination thereof in addition to the metal. The shapedform can be a monolith, honeycomb or foam or shaped units such aspellets, extrudates or granules. Supports includes, refractory oxides,alumina, hydrated alumina, metal-aluminate, silica, titania, zirconia,zinc oxide, aluminosilicates, zeolites, metal carbonate, clay, cement,and carbon, or any mixture thereof. Binders that may be used to preparethe shaped units include clays, cements, calcium aluminate cements, andorganic polymer binders such as cellulose binders, or any mixturethereof. The methods of the present invention of sulfurizing the metalcontaining particles according are illustrated with reference to FIGS.1A-1C.

Treatment of metal containing particles in accordance with inventionsdescribed herein may include contacting a bed of metal containingparticles with a gaseous stream comprising hydrogen sulfide and inertgas in a vertical reactor. In the reactor, at least a portion of theunsulfided metal containing particles can be sulfided in the absence ofhydrogen by contact of the particles with a gaseous stream that includeshydrogen sulfide and inert gas. FIGS. 1A-1C are schematics of acontacting system 100 for sulfurizing metal containing particles in theabsence of hydrogen in accordance with the methods of the presentinvention described throughout. Referring to FIG. 1A, the system 100includes a vertical reactor 102. Vertical reactor has a height dimensiongreater than its width dimension. Vertical reactor 102 can include lowergas inlet 104 and gas outlet 106. The gas inlet 104 can be positioned atthe bottom or proximate the bottom portion of the vertical reactor 102.The gas outlet 106 can be positioned at the top or upper portion of thevertical reactor 102. Unsulfided metal containing particles 110 and/ormetal containing particles that need to be resulfided can be positionedin the reactor 102. The metal contain particles are layered in thereactor vessel in a random formation. In certain embodiments, a volumeof metal particles in the reactor 102 is in a range from about 10-90vol. %, about 20-50 vol. %, or about 30-40 vol. % of a total volume ofthe reactor. In some aspects of the invention, unsulfided particles 110can be heated to a temperature of 50 to 200° C., 60 to 150° C., 70 to130° C., or 80 to 100° C. prior to loading the reactor 102. In someaspects of the invention, particles 110 are heated in the reactor 102using heating component 112. The heating component 112 can include aheating element, cooling element, be a shell or jacket that allows heattransfer fluid to circulate around the reactor 102, or inside coilsinternal to the reactor 102, or any combination thereof. In certainembodiments, the contacting system 100 is off site or ex situ to thesystem where the particles will be used. The gaseous stream 108 thatincludes hydrogen sulfide and inert gas enters the vertical reactor 102through gas inlet 104. The gaseous stream 108 can have from 1 to 20 vol.%, 2 to 20 vol. %, 5 to 15 vol. %, or 6 to 12 vol. % of hydrogensulfide. In some aspects of the invention, the amount of hydrogensulfide is determined based on the molar amount of metal to be sulfided.The inert gas can include nitrogen, carbon dioxide, argon, methane, orany combination thereof. A molar ratio of the inert gas to hydrogensulfide in the gaseous stream is at least 5:1, 10:1, 30:1 or 50:1. Forexample, the molar ratio of the combination of nitrogen and carbondioxide to hydrogen sulfide can be at least 5:1, 20:1, or 50:1. Contactof hydrogen sulfide in the gas stream 108 with the unsulfided metalcontaining particles 110 can result in sulfided metal containingparticles 114, partially sulfided metal particles 116, and unsulfidedmetal particles 110 as shown in FIG. 1B. In some aspects of theinvention, 10%, 20%, 30%, 40%, 50%, 80%, or up to 90% of the bed ofmetal containing particles is converted into the sulfided metalcontaining particles 114. A majority of the produced sulfided metalcontaining particles 114 are positioned closer to the inlet 104 whencompared to unsulfided metal containing particles 110 positioned closerto the outlet 106 of the reactor 102. Contact of the gaseous stream 108results in spent gas stream 118. Spent gas stream 118 exits the reactor102 through gas outlet 106. Spent gas stream 118 can include, water,inert gas, carbon dioxide, and some residual hydrogen sulfide. Waterand/or carbon dioxide is formed due to the reaction of the hydrogensulfide with the unsulfided metal. In some aspects of the invention, thespent gas stream contains little to no hydrogen sulfide gas.

Contacting conditions in the reactor 102 include, but are not limitedto, temperature, pressure, gaseous stream flow, or any combinationthereof. Contacting conditions in some embodiments are controlled toproduce a specified amount of sulfided metal containing particles withcertain amounts of sulfur. Temperature in the reactor 102 can be 250° C.or less, 200° C. or less, 150° C. or less, or 100° C. or less, or from20 to 250° C. Temperature in the reactor 102 can be controlled byadjusting the setting of the heating and/or cooling elements ortemperature of the fluid used in the heating component 112. Pressure ina contacting zone may range from about ambient to 195 kPa, 0.1 to 100kPa, 1 to 20 kPa, or 5 to 10 kPa. The LHSV of the gaseous stream candepend on the shape and/or size of reactor and the metal containingparticles, but can generally range from about 1-100 h⁻¹, about 5-50 h⁻¹,or about 10-30 h⁻¹. The LHSV of the gaseous stream 108 is such that nofluidization or ebullition of the metal containing particles 110 bedoccurs, but a majority of the metal containing particles can vibrate orshake during contacting. In some embodiments, the metal containingparticles 110 are substantially stationary during contact with thegaseous stream 108. In some aspects, of the invention the LHSV iscontrolled such that the metal containing particles 110 are not mixed.For example with reference to FIGS. 1A and 1B, the particles in themiddle portion of the reactor 102 do not move to the lower portion ofthe reactor and the particles in the upper portion of the reactor 102 donot move to the middle portion of the reactor during contact with thegaseous stream 108.

In contrast to the present invention, FIGS. 2A-2C are schematics ofmetal containing particles of sulfiding using mixing methods. As shownin FIG. 2A, as gaseous stream 108 is provided to the reactor 102, theunsulfided metal containing particles 110 to fluidized or ebullated inthe reactor, which suspends and mixes the metal containing particles inthe reactor 102. Thus, the metal containing particles are moved relativeto each other. As the metal containing particles are sulfided, a mixtureof sulfided, unsulfided particles, and partially sulfided particles isproduced throughout the reactor 102, as shown in FIG. 2B. After thegaseous stream 108 is discontinued, the mixture of particles fall fromthe top of the reactor 102 to the bottom of the reactor as shown in FIG.2C. Thus, when the metal containing particles are removed from thereactor after the sulfiding process, the metal containing particles area mixture of sulfided, unsulfided and partially sulfided metalcontaining particles.

After a period of time, or until a desired amount of the metalcontaining particles 110 are sulfided, the flow of gas may be slowed ordiscontinued. For example, a known amount of hydrogen sulfide based onthe metal content of the metal containing particles may be provided tothe reactor. After the desired amount of hydrogen sulfide has beenprovided, the flow of hydrogen sulfide is discontinued and only inertgas is provided to the reactor. The gas exiting the reactor may betested for hydrogen sulfide to determine that none, or substantiallynone, of the hydrogen sulfide is leaving the reactor. In some aspects ofthe invention, the reactor 102 may be flushed with an inert gas toremove any excess hydrogen sulfide gas to an acceptable level, typicallyless than 100 ppm. A portion, or all, of the sulfided metal containingparticles 114 can then be removed via conduit 120 at the bottom of thereactor 102, and additional unsulfided metal containing particles 110are added to the top portion of the reactor via conduit 122. The removaland addition of the particles 114 and 110 can be done simultaneously orin a stepwise manner. Removal of the sulfided metal particles 114,allows partially sulfided metal particles 116 to move to the bottomportion of the reactor 102, and the sulfiding process can be resumed asshown in FIG. 1C. Since, the metal containing particles are notsuspended or substantially mixed in the reactor 102, the sulfided metalcontaining particles can be removed and have 5% or less, 1% or less, orno unsulfided or partially sulfided particles in the mixture. In someaspects of the invention, after the partially sulfided metal particles116 have moved to the bottom portion of the reactor 102, no metalcontaining particles 110 are added to the top of the reactor. Thesulfiding process is then resumed and the partially sulfided particlesare sulfided and then removed from the reactor. The resulting sulfidedmetal particles 114 can be at least 99% or 100% sulfided. In someaspects of the invention, the system is automated and a hydrogen sulfidesensor is positioned in outlet 106 to monitor the amount of hydrogensulfide leaving the reactor. Once the amount of hydrogen sulfide dropsto a predetermined level or is undetected, the metal sulfided particlesare removed from the reactor 102 via conduit 120. The sulfided metalcontaining particles 114 can be packaged in containers under an inert(e.g., nitrogen or carbon dioxide) atmosphere. The sulfided metalcontaining particles 114 can be transported to another facility to beused in the manufacture of sorbents or catalysts or be used directly assorbents or catalysts.

The system 100 can be automated with suitable sensors and/orthermocouples to acquire data during the process. The acquired data canbe transmitted to one or more computer systems. The computer systems caninclude components such as CPUs or applications with an associatedmachine readable medium or article which may store an instruction or aset of instructions that, if executed by a machine, may cause themachine to perform a method and/or operations in accordance with themethods of the present invention. For example, upon input of data fromthe sensors and/or thermocouples, control the flow of the gaseousstream, opening or closing of valves associated with gas inlet 104, gasoutlet 106, temperature element 112, reactor outlet 120 and reactorinlet 122. Such a machine may include, for example, any suitableprocessing platform, computing platform, computing device, processingdevice, computing system, processing system, computer, processor, or thelike, and may be implemented using any suitable combination of hardwareand/or software. The machine-readable medium or article may include, forexample, any suitable type of memory unit, memory device, memoryarticle, memory medium, storage device, storage article, storage mediumand/or storage unit, for example, memory, removable or non-removablemedia, erasable or non-erasable media, writeable or re-writeable media,digital or analog media, hard disk, floppy disk, Compact Disk Read OnlyMemory (CD-ROM), Compact Disk Recordable (CD-R), Compact DiskRewriteable (CD-RW), optical disk, magnetic media, magneto-opticalmedia, removable memory cards or disks, various types of DigitalVersatile Disk (DVD), a tape, a cassette, or the like. The instructionsmay include any suitable type of code, such as source code, compiledcode, interpreted code, executable code, static code, dynamic code, andthe like. The instructions may be implemented using any suitablehigh-level, low-level, object-oriented, visual, compiled and/orinterpreted programming language, such as C, C++, Java, BASIC, Perl,Matlab, Pascal, Visual BASIC, assembly language, machine code, and soforth. The computer system may further include a display device such asmonitor, an alphanumeric input device such as keyboard, and adirectional input device such as mouse.

EXAMPLES

The present invention will be described in greater detail by way ofspecific examples. The following examples are offered for illustrativepurposes only, and are not intended to limit the invention in anymanner. Those of skill in the art will readily recognize a variety ofnoncritical parameters which can be changed or modified to yieldessentially the same results.

Example 1 Sulfurization of Metal Containing Particles

Sorbent (6000 lbs.) containing 8% copper oxide precipitated on aluminawas placed in a reactor having a length to diameter ratio of 6.0. Thesorbent was preheated to 80° C. using a preheated inert stream of 40%carbon dioxide, 60% nitrogen and hot inert heating elements. Hydrogensulfide was introduced to the inert gas stream at a ratio of 4 volumepercent and the gaseous mixture as introduced at the bottom of thereactor at a LHSV of 45 h⁻¹. The concentration of hydrogen sulfide inthe effluent gas was monitored. When the concentration in the effluentgas reached 500 ppm, the hydrogen sulfide addition was discontinued.When the level in the effluent gas reached 5 ppm, the flow of inertgases was reduced to a LHSV of 2 h⁻¹. A portion (1,000 lbs.) of sulfidedsorbent was emptied from the bottom of the reactor and unsulfidedsorbent (1,000 lbs.) was added to the top of the reactor, while beingpurged with inert gas. The sulfided sorbent was analyzed for sulfurusing a LECO CS-230 analyzer and determined to have a 97% conversion ofcopper oxide to copper sulfide (CuS).

The invention claimed is:
 1. A method of sulfurizing metal containingparticles comprising: (a) contacting a bed comprising metal containingparticles with a gaseous stream comprising hydrogen sulfide atconditions sufficient to produce sulfided metal containing particles andpartially sulfided metal containing particles in the bed, wherein thegaseous stream is introduced into the bottom portion of the bed and anyunreacted hydrogen sulfide is removed through an outlet proximate anupper portion of the bed; (b) removing of the sulfided metal containingparticles from the bed; and (c) providing unsulfided metal containingparticles to the top portion of the bed, above the partially sulfidedmetal containing particles; wherein step (a) is performed at ambientpressure to 195 kPa; wherein steps (a), (b), or (c), or any combinationsthereof are performed in the absence of hydrogen gas; and wherein themetal containing particles remain substantially stationary during step(a).
 2. The method of claim 1, wherein the method is performed off-site.3. The method of claim 1, wherein the sulfided metal containingparticles are positioned below the partially sulfided metal containingparticles.
 4. The method of claim 1, wherein steps (b) and (c) are donesequentially.
 5. The method of claim 1, wherein steps (b) and (c) aredone simultaneously.
 6. The method of claim 1, wherein at least 25% ofthe initial amount of metal containing particles are sulfided.
 7. Themethod of claim 1, wherein a majority of the produced sulfided metalcontaining particles are removed from the bottom portion of the bed. 8.The method of claim 7, wherein substantially all of the sulfided metalcontaining particles are removed from the bed, and wherein 100% of theremoved metal containing particles are sulfided.
 9. The method of claim1, wherein the gaseous stream further comprises an inert gas selectedfrom nitrogen, argon, helium, methane, carbon dioxide, and mixturesthereof.
 10. The method of claim 1, wherein the gaseous stream flows inan upwardly direction through the bed.
 11. The method of claim 1,wherein the bed is vertical, and gaseous stream flows from the bottomportion of the reactor, through the bed, and then out the outlet. 12.The method of claim 11, wherein water and unused hydrogen sulfide arecomprised in the gaseous stream removed through the outlet.
 13. Themethod of claim 1, wherein contacting is performed at a temperature of250° C. or less and a pressure from 101 kPa to 195 kPa.
 14. The methodof claim 1, wherein unsulfided metal containing particles are comprisedin the bed after contact with the gaseous stream, and the unsulfidedmetal containing particles are positioned above the partially sulfidedmetal particles.